Dynamic Byte Array in C# by Socket Programming [List<byte> does not work]

Question

I'm sending to a device a request as byte array and I want to receive the anwser device gives.

...
Socket deviceSocket = new Socket(server);
List<byte> coming = new List<byte>();
...
deviceSocket.Receive(coming)

Here the program gives error: Error 1
The best overloaded method match for 'System.Net.Sockets.Socket.Receive(byte[])' has some invalid arguments Error 2
Argument '1': cannot convert from 'System.Collections.Generic.List' to 'byte[]'

How can I solve it ?

Thanks.

Answer 1

as the error tells use byte[]

Socket deviceSocket = new Socket(server);
byte[] coming = new byte[buffersize];
...
deviceSocket.Receive(coming)

See also this

Answer 2

The Socket.Receive() method will fill a buffer with as much data as it can fit, or as much data is available, whichever is lower.

If you know all your messages are under 2048 bytes then you could declare your buffer as follows:

byte[] buffer = new byte[2048];
int bytesReceived = 0;
// ... somewhere later, getting data from client ...
bytesReceived = deviceSocket.Receive( buffer );
Debug.WriteLine( String.Format( "{0} bytes received", bytesReceived ) );
// now process the 'bytesReceived' bytes in the buffer
for( int i = 0; i < bytesReceived; i++ )
{
    Debug.WriteLine( buffer[i] );
}

Of course you probably want to do something more than write the bytes to the debug output, but you get the idea :)

You still need to be aware that you may get incomplete data, if the client broke the message into multiple packets then one might come through (and be received) and then later another. It's always good to have some way of telling the server how much data to expect, then it can assemble the complete message before processing it.